GB2142952A

GB2142952A - Curtain walling with allowance for thermal expansion and contraction of panels

Info

Publication number: GB2142952A
Application number: GB08413133A
Authority: GB
Inventors: Pierre Legrand; Pierre Barthel
Original assignee: Freyssinet International STUP SA
Current assignee: Freyssinet International STUP SA
Priority date: 1983-05-25
Filing date: 1984-05-23
Publication date: 1985-01-30
Also published as: FR2546555A1; GB8413133D0; GB2142952B; IT1198843B; IT8409410A0; JPS59224752A; DE3419457A1; JPH0452336B2; FR2546555B1

Abstract

Reinforced concrete panels 4 each have a height greater than 5 meters. Each panel is suspended by suspension means 6 adjacent the top edge of the panel and is retained against the building by a slidening fastener 12 located towards the bottom of the panel. Sliding fastener 12 comprises metal case 121 embedded in the rear face of panel 4, and defines a T-shaped slot therein. The bolt of a bolt-nut assembly 122 is embedded in floor-slab 34 and the threaded end passes through the vertical stem of the T. The nut engages on the bolt in casing 121 to prevent outward movement of panel 4. A resilient element 123 may be provided round the shank of the bolt to prevent inward movement of the panel. <IMAGE>

Description

SPECIFICATION Improvements in or relating to curtain-walling The present invention relates to curtain walling, and to panels for use in curtain-walling.

Curtain-walling is an exterior or cladding wall provided on a building, and has the feature that it ddes not support any floors. Thus curtain-walling is mounted on a supporting frame-work provided by the building which they cover, and the curtainwalling performs the function of providing an external covering for the building. Frequently curtainwalling provides a sealed separation between the exterior of a building and the interior thereof.

It has been proposed to provide curtain-walling constituted by panels made of metal, plastic material, wood or the like. Such panels have the disadvantage of being relatively expensive to fabricate, and may also suffer from various disadvantages such as the necessity to provide special protection against humidity and ageing, low resistance to shocks, poor thermal insulation, and availability only as relatively small elements. If the panels can only be fabricated as elements of a small size, a large number of panels must be utilised to form a curtain-wall and there are thus many joints between adjacent panels which may have to be sealed.

In an attempt to overcome at least some of these disadvantages and drawbacks it has been proposed to produce panels for use in forming a curtain-wall from prestressed concrete. However, such panels have only be designed to be relatively small extending at most over the height of a single storey.

The present invention seeks to provide panels for use in forming curtain-walling, and curtain-walling formed from such panels, each panel being dimensioned to extend over the height of at least two storeys, the panels, and the curtain-walling, being such that the above-mentioned disadvantages are reduced or obviated.

According to this invention there is provided a prestressed rectangular concrete panel for use in forming a curtain-wall, said panel having a length greater than 5 meters, said panel having means at one end for suspending the panel from a building and having a fastening means located at a position spaced from said suspension means, the fastening means being adapted to provide a sliding fastening to a fixed point on a building. Preferably the panel has a length of the order of 10 meters.

The suspension means may constitute one or more eyelets formed adjacent the upper edge of the panel, or mass constitute one or more pins protruding from the top of the panel, each pin being provided with a through-aperture therein.

Preferably the fastening means constitutes means embedded in the rear face of the panel defining a slot located substantially in the plane of the rear face of the panel, said slot being adapted to engage a nut-and-bolt assembly. The reinforcing may be concentrated in the region of the suspension means and in the region of the fastening means, and the means pre-stressing the panel may be supplemented by reinforcing iron rods and the like. The panel may define one or more window openings.

Preferably the panel is provided with means to form a seal between said panel and a further similar panel located adjacent said panel.

According to another aspect of this invention there is provided a curtain-wall, said curtain-wall being constituted by a plurality of pre-stressed rectangular concrete panels, each panel having a length greater than 5 meters, each panel being suspended from a building by a suspension means located adjacent the upper edge of the panel, said panel also being fastened to a fixed point on a building at a position remote from the upper edge of the panel by fastening means which provide a sliding fastening relative to the fixed point on the building. Preferably each panel has a length of the order of 10 meters.

The suspension means on each panel may be one or more eyelets adjacent the upper edge thereof, the eyelets engaging pins or other corresponding elements protruding from the building, or alternatively may be constituted by a one or more lugs protruding from the top of the panel, each lug being provided with a through aperture therein, the lugs cooperating with fork elements protruding from the building, each fork element protruding from the building being a bifurcated element provided with throughapertures therein connecting pins passing through the apertures in the bifurcated element and the apertures in the pins protruding from the top of the panel.

Preferably said fastening means constitute means embedded in the rear face of each panel defining a slot located substantially in the plane of the rear face panel, said slot engaging a nut-and-bolt assembly protruding from the building.

Advantageously resilient means are located between the said rear face of the panel and the building, said resileint means surrounding said nut-and-bolt assembly.

Preferably the said resilient means constitutes a resilient strip sealing the space between the rear of the panel and the building.

Conveniently the reinforcing in each panel is concentrated in the region of the suspension means and in the region of the fastening means. Advantageously the means pre-stressing the panels are supplemented by reinforcing rods and the like.

Conveniently at least some of the panels define one or more window openings.

Preferably the panel elements are over-lapped, alternate elements being rear elements and the remaining elements being forward elements. Alternatively the panels are overlapped in a uniform manner.

Advantageously the panels are provided with sealing means between overlapped panels to seal the panels together.

In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described by way of example with reference to the accompanying drawings in which: Figure 1 is a schematic vertical sectional view of a building equipped with a curtain-wall in accordance with the invention; Figure 2 is a front view, on a slightly larger scale, of a component panel used in the curtain-wall of Figure 1; Figure 3 is a vertical sectional view, on a much larger scale, of a detail of a building provided with a curtain wall in accordance with the invention, showing the method of suspending a panel and the method of slidingly fastening another panel; Figure 4 is a horizontal section of Figure 3 along theline IV-iV;; Figure 5 is a vertical sectional view showing an intermediate sliding fastening of a curtain-wall provided with window apertures; Figure 6 is a horizontal sectional view taken on the line VI-VI of Figure 5 showing the alternate overlapping of panels in a curtain wall in accordance with the invention; Figure 7 is an elevational view of the sliding fastening illustrated in Figure 5; and Figure 8 illustrates schematically an alternative method of over-lapping the panels of a curtain-wall in accordance with the invention.

Referring initially to Figure 1 of the accompanying drawings a building is illustrated which has five floors. The main structure of the building 1 is constituted by vertical load bearing walls 2. Horizontal slabs 3 are provided to constitute the various floors of the building. Slab 30 is a ground floor slab resting directly on the foundations of the building.

Slab 31 constitutes the ceiling of the ground floor and the floor of the first floor of the building.

Similarly slabs 32, 33, 34 each constitute both a ceiling and a floor.

It will be noted that the peripheral edges of the slabs are cantilevered beyond the load bearing wall 2 and a curtain-wall constituted by thin concrete panels 4 is provided at the end of the building. Each panel 4 extends vertically over the whole height of the ground floor and also over the whole height of the first three storeys. Each concrete panel is suspended from the edge of the slab 34.

The thickness of the concrete panels 4 is very small - it is between 5 and 10 cm, preferably being of the order of 8 cm. To minimise any risk of the suspended panels 4 cracking because of their own weight, they are prestressed by adherence or by "adhering wires". In other words, said panels 4 are reinforcsd during manufacture by metal wires or cables 5, which are illustrated in Figure 2. The wires or cables 5 are stretched and are located in a mould, shuttering or"bench" whilst in the stretched condition. Concrete is then poured into the mould, shuttering or "bench" and is permitted to cure or harden. The tension in the cables is released after the concrete has set, and because of the intimate adherence between the cables and the concrete, cables exert a permanent densifying force on the concrete. This force ensures the coherence of the panels.In addition to the metal wires or cables 5 further reinforcing elements such as iron rods or bars may be located in the panels if necessary. It is preferred that the reinforcing is provided with greatest density around the suspension elements and the sliding connection elements that will be described hereinafter.

Methods of manufacturing pre-stressed concrete panels have been proposed before and reference may be made to French Patent Specification No.

1,447,819, which tcaches the manufacture of a thin pre-stressed concrete panel. However, this prior concrete panel was not intended to form a suspended curtain-wall, and it is to be noted that the reinforcements provided in that panel were not concentrated in specific zones.

The face of each panel which is to be exposed to the exterior of the building when it is in its final mounted position is preferably the face of the panel which is located at the bottom of the concrete mass during the fabrication of the panel. Thus, any desirable configuration can be given to this face during the moulding process. In particular, the panel may be provided with a shape or configuration corresponding to the shape or configuration of a wall made of cut stone or brick facings, by giving the bottom of the mould or "bench" a profile complementary to the profile desired to be exhibited by the panel. Alternatively, the panel may be given a "pebble-dash" finish by providing appropriate gravel or pebbles in the lower part of the mould before the concrete is poured into the mould.

Various other techniques may be utilised to provide the panel with a desired external appearance.

It is to be appreciated that the concrete utilised in forming the panel may be provided with artificial colour so that the resultant panel has a colour corresponding to that of natural stone or that of brick.

The panels 4 are rectangular, the panels being elongate in the vertical direction. The longitudinal direction of each panel is greater than five meters, and in the illustrated embodiment of the order of 10 metres, namely between nine and eleven metres.

The width of each panel is preferably less than or equal to 2.40 metres. Panels of this width may easily be transported by road in a horizontal position.

Panels of five metres height may be found to be useful in the construction of buildings only having two superimposed storeys, such as a two storey house. The curtain-walls of the present invention lend themselves particularly well to the construction of such units, which have a certain number of advantages over single storey constructions, in particular the increase in habitable volume for a given price. Such five meter panels may also be utilised in the construction of blocks of relatively high rise maisonettes. An advantage of such buildings is that the requirements of the intermediate floor of a maisonette are less strigent than for the other floors of such a block, particularly from the points of view of sound insulation,fire resistance and of the load to be supported.

It will be understood that the panel of the length of the order of 10 metres corresponds then to two superimposed maisonettes.

The applicant has discovered that, surprisingiy, despite the substantial length of a panel of approximately 10 metres, panels of this type are relatively easy to manufacture, and can be transported and installed without undue difficulty. The pre-stressing present in the panels allows the weight of the panels to be supported without any substantial risk of cracking.

It is to be appreciated that panels may be produced having various widths. It is envisaged that a range of panels will be produced having widths between 30 cms and 2.40 metres. It is envisaged that panels may be selected from such a range of panels to provide a suitable curtain-wall for virtually any building.

In order to facilitate the eventual suspension of each panel for in its final position on the building, as well as to facilitate the handling of the panel during removal of the panel from the mould or "bench" and during transportation, it is peferred that each panel is provided with at least one suspension element 6 in the region of the upper edge of the panel. As shown in Figure 2 the suspension element 6 may be constituted by an eyelet or aperture 7 formed in the upper region of the panel. A panel provided with such eyelets may be mounted in position by sliding the eyelets 7 onto horizontal pins or eye-bolts 7 which protrude from the periphery of the floor slab 34 from which the panel is to be suspended.

However, Figures 3 and 4 illustrate another arrangement in which the suspension element 6 is constituted by a vertical lug 9 having a base 91 embedded in the upper edge of the panel 4 and a head 92 protruding above the upper edge of the panel. The head 92 is provided with a through-going aperture 93. A horizontal fork member 10 has a foot 10, embedded in the floor slabe 34, and the arms 102 of the fork 10 embrace the above-mentioned head 92.

Each arm 102 is provided with a bore 103, these bores being aligned with the through-going apertures 93. A pin 11 passes through the bores 103 and the aperture 93 thus suspending the panel from the building.

Since the ratio between the thickness and the length of each panel 4 is very small, the panels may tend to behave like a slightly flexible sheet. In order to minimise any risk of the panels flapping in the wind, it is preferred that each panel is fastened to the framework of the building 1 adjacent the base of the panel, and possibly at at least one intermediate level by means of an appropriate fastener 12. The fastener 12 is adapted to prevent the panel from moving horizontally in the direction perpendicular to the plane of the panel, but is also designed to allow a vertical sliding movement of the panel relative to the building. The reason for this is that the panel may expand or contract in response to changes in the ambient temperature and thus this sliding effect must be provided, since otherwise thermal deformations would tend to develop troublesome stresses.

The sliding fastener is illustrated in Figures 5 and 7, and referring to these Figures it is to be noted that the sliding fastener 12 comprises a metal case 121 embedded in the rear face of the panel 4 and defining an open slot of "T" configuration which is effectively defined in the plane of the rear face of the panel. A bolt-nut assembly 122 is provided. The head of the bolt is embedded in the corresponding floor slab 32 and the threaded end passes through the slot constituting the vertical stem of the "T". A nut is engaged on the threaded end of the bolt within the casing 12, engaging the interior of the metal casing 121 on either side of the vertical portion of the slot therein. Thus outward movement of the panel 4 is prevented.An element 123 of resilient material may be provided surrounding the threaded shank of the bolt, located between the front face of the casing 12 and the edge of the floor panel 32 to prevent any inward movement of the panel. The casing 12 is so dimensioned and configured that when the panel is initially suspended in position the bolt will extend through the slot, and the nut may then be introduced into the casing and may be tightened, the workman gaining access to the nut through the portion of the slot that defines the head of the "T".

The resilient material surrounding the bolt may be constituted by resilient horizontal strips 123 which extend across the entire width of the panel. Such strips will effectively close the air gap defined between the panel and the edge of the floor slab 34 (see Figure 3). As can be seen in Figure 2 the quantity of reinforcement provided in the panel is concentrated in the vicinity of the upper suspension elements and in the region of the sliding fasteners 12.

The reinforcing in these regions may include iron bars and the like or may be constituted by the wires or cables that provide the pre-stressing to the concrete panel.

In orderto minimise the formation of heat and/or sound bridges between the panels 4 and the adjacent floor slabs cushions 14 (Figure 3), which may be formed of an insulating material, are located between the panels and the adjacent floor slabs.

As can be seen in Figure 3 the curtain wall is associated with an internal dividing wall 15 extending parallel to the panels 4 and separated from the panels by means of an air gap 16. The dividing walls 15 are built directly on the floor slabs and may be fabricated from light, thermally insulating materials.

The walls 15 may be provided with an internal facing 15, constituted by fibre board, plaster board, or even plaster.

In a preferred embodiment a drip-sheet or flashing 17 is provided which covers the upper edge of each panel 4 so as to protect it from the rain (Figure 3).

In view of the thin nature of the panels it is difficult to arrange things so that the panels abut each other edge-to-edge and are sealed adequately. Thus, in a preferred embodiment, the panels are mounted on the building in a mutual overlapping arrangement, with appropriate seals being provided between the panels. In Figures 5 and 6 the overlapping is an alternate nature, with alternate panels being "rear" panels and the remaining panels being "front" panels. In the overlapping regions a seal is provided by means of complementary shaped sections 18 which may be embedded in one or both panels during the moulding process and by means of resilient seals which are compressed between the panels. In the arrangement shown in Figures 5 and 6 three adjacent panels are illustrated, the two endmost panels being solid and the central panel being provided with window apertures 20.

Figure 5 illustrates the vertically sliding mounting 12 of the central panel on the intermediate floor slab 32, the part of the panel located below the floor slab 32 being located above the window 20 of the lower storey, and the part of the panel located above the floor slab 32 extending up to the window 20 of the upper storey.

The panels 4 adjacent the apertured central panel project slightly outwardly from the frontage of the building with respect to this central panel. However, all the panels are suspended from and attached to the horizontal floor slabs in the way described above, the only difference being that the pins or forks which support them extend from the floor slabs by different distances depending upon whether the panel is a rear panel or a "front" panel.

The horizontal periphery of the floor slabs 3 may be provided with a crenelated form so that the shape of the floor slabs corresponds with the shape defined by the overlapping panels. This may enable fixing bolts or pins of uniform length to be utilised.

Instead of the panels overlapping in the manner described above, the panels may be overlapped in a uniform manner, providing a "fish scale" structure, as shown in a top view in Figure 8. In such a case the axes 23 of the supporting pins or the like are no longer strictly perpendicular to the mean plane of the panels to be supported and appropriate modifications must be made to the suspension elements.

Whilst specific embodiments of the invention have been described it is to be noted that curtain-walls in accordance with the invention may be utilised for other purposes than defining the exterior of a building with vertical walls. Thus the walls may be slightly slanted or, in certain circumstances may be internal walls. Whilst the panels utilised in forming the preferred embodiment of a curtain wall in accordance with the invention are substantially flat, it is conceivable that the panels may be reinforced by longitudinal and/or transverse ribs.

Claims

1. A prestressed rectangular concrete panel for use informing a curtain-wall, said panel having a length greaterthan 5 meters, said panel having means at one end for suspending the panel from a building and having a fastening means located at a position spaced from said suspension means, the fastening means being adopted to provide a sliding fastening to a fixed point on a building.

2. A panel according to claim 1, wherein the panel has a length of the order of 10 meters.

3. A panel according to claim 1 or claim 2, wherein the suspension means constitutes one or more eyelets formed adjacent the upper edge of the panel,

4. A panel according to claim 1 or 2, wherein the suspension means constitutes one or more pins protruding from the top of the panel, each pin being provided with a through-aperture therein.

5. A panel according to any one of the preceding claims, wherein the fastening means constitutes means embedded in the rear face of the panel defining a slot located substantially in the plane of the rear face of the panel, said slot being adapted to engage a nut-and-bolt assembly.

6. A panel according to any one of the preceding claims, wherein the reinforcing is concentrated in the region of the suspension means and in the region of the fastening means.

7. A panel according to any one of the peceding claims, wherein the means pre-stressing the panel are supplemented by reinforcing iron rods and the like.

8. A panel according to any one of the preceding claims, defining one or more window openings.

9. A panel according to any one of the preceding claims provided with means to form a seal between said panel and a further similar panel located adjacent said panel.

10. A curtain-wall, said curtain-wall being constituted by a plurality of pre-stressed rectangular concrete panels, each panel having a length greater than 5 meters, each panel being suspended from a building by a suspension means located adjacent the upper edge of the panel, said panel also being fastened to a fixed position on a building at a point remote from the upper edge of the panel by fastening means which provide a sliding fastening relative to the fixed point on the building.

11. A wall according to claim 10, wherein each panel has a length of the order of 10 meters.

12. Awall according to claim 10 or claim 11, wherein the suspension means on each panel is one or more eyelets adjacent the upper edge thereof, the eyelets engaging pins or other corresponding elements protruding from the building.

13. A wall according to claim 10 or 11, wherein the suspension means on each panel is constituted by a one or more lugs protruding from the top of the panel, each lug being provided with a through aperture therein, the lugs cooperating with fork elements protruding from the building, each fork element protruding from the building being a bifurcated element provided with through-apertures therein, connecting pins passing through the apertures in the bifurcated element and the apertures in the pins protruding from the top of the panel.

14. A wall according to any one of claims 10 to 13, wherein said fastening means constitute means embeded in the rear face of each panel defining a slot located substantially in the plane of the rear face panel, said slot engaging a nut-and-bolt assembly protruding from the building.

15. Awall according to claim 14, wherein resilient means are located between the said rear face of the panel and the building, said resilient means surrounding said nut-and-bolt assembly.

16. Awall accordingtoclaim 15,whereinthe said resilient means constitutes a resilient strip sealing the space between the rear of the panel and the building.

17. Awall according to any one of claims 10 to 16, wherein the reinforcing in each panel is concentrated in the region of the suspension means and in the region of the fastening means.

18. Awall according to any one of the claims 10 to 17, wherein the means pre-stressing the panels are supplemented by reinforcing rods and the like.

19. Awall according to any one of claims 10 to 18, wherein at least some of the panels define one or more window openings.

20. A wall according to any one of claims 10 to 19, wherein the panel elements are over-lapped, alternate elements being rear elements and the remaining elements being forward elements.

21. A wall according to any one of claims 10 to 19, wherein the panels are overlapped in a uniform manner.

22. A wall according to claim 20 or 21, wherein the panels are provided with sealing means between overlapped panels to seal the panels together.

23. A prestressed rectangular concrete panel substantially as herein described with reference to and as shown in the accompanying drawings.

24. A curtain-wall substantially as herein described with reference to and as shown in Figures 1 to 7 of the accompanying drawings.

25. A curtain-wall according to claim 10 and substantially as herein described with reference to and as shown in Figure 8 ofthe accompanying drawings.

26. Any novel feature or combination of features disclosed herein.